Liquid crystal display having no gate PCB and FPC

ABSTRACT

The present invention relates to a liquid crystal display having no gate PCB and FPC. This comprises: a liquid crystal panel formed by an assemble an array substrate and a color filter substrate with a liquid crystal layer interposed therebetween; a plurality of source TCPs and gate TCPs, which are attached to a source and a gate of the liquid panel, respectively, and mounted with a gate driver IC and a source driver IC, respectively; a source PCB connected to the source TCPs and serving to apply a given driving signal to the source driver IC; a LOG formed on the liquid crystal panel such that a signal from the source PCB is applied to the gate driver IC via the gate TCPs; and transfers formed between the substrates at edges of the liquid crystal panel such that common voltage is applied to the color filter substrate. In this liquid crystal display, the LOG consists of gate driver IC-driving signal lines without having a common line for connecting the transfers with each other. According to the present invention, the common line is eliminated from the LOC so that a margin in a LOC layout can be ensured. This can reduce the resistance of the LOC to a suitable level and thus improve the screen quality of the liquid crystal display.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a liquid crystal display, andmore particularly, to a Vcom line layout in a liquid crystal displayhaving no gate PCB (printed circuit board) and FPC (flexible printedcircuit).

[0003] 2. Description of the Prior Art

[0004] A liquid crystal display, which has been developed as asubstitute for CRT (cathode ray tube), can realize lightweight, thinthickness and low power consumption, so that it is in the spotlight asthe next-generation image display device. Currently, various studies toimprove the display performance of the liquid crystal display areconducted.

[0005] Generally, this liquid crystal display comprises: a liquidcrystal panel as a substantial display element; gate and source PCBs(printed circuit boards) as driving circuits serving to apply a givensignal to the liquid crystal panel; a FPC (flexible printed circuit)connecting the PCBs with each other; a TCP (top carrier package) or COF(chip on film) connecting the liquid crystal panel to PCBs and mountedwith a driver IC; a backlight unit disposed below the liquid crystalpanel and serving as a light source; and means for assembling the aboveelements.

[0006] Meanwhile, to reduce the cost and weight of the liquid crystaldisplay, there was recently proposed a liquid crystal display structurein which a LOG (line-on-glass) is formed on the liquid crystal panel,particularly an array substrate of the liquid crystal panel, withomission of the gate PCB and the FPC, and this LOC is connected to thesource PCB such that a given signal for driving the gate driver IC aresupplied.

[0007] FIGS. 1 to 4 are top views showing liquid crystal displaysaccording to the prior art. Specifically, FIG. 1 shows a structurehaving the gate PCB and the FPC, FIG. 2 shows a structure having no FPC,and FIG. 3 shows a structure having no the gate PCB and the FPC.

[0008] In FIGS. 1 to 3, the reference numeral 1 designates a source PCB,the reference numeral 2 designates a gate PCB, the reference numeral 3designates a FPC, the reference numeral 4 designates source TCPs, thereference numeral 5 designates gate TCPs, the reference numeral 6designates an array substrate, the reference numeral 7 designates acolor filter substrate, the reference numeral 8 designates a displayregion, the reference numeral 9 designates a LOC, the reference numeral10 designates a common line, and the reference numeral 11 designatestransfers.

[0009] Referring to FIG. 2, in the case of the liquid crystal displayhaving no FPC 3, the LOG is additionally formed on the array substrate 6of the liquid crystal panel in order to transmit a driving signal to thegate driver IC. Examples of such a driving signal include gate lowvoltage, gate high voltage, STV, CPV, OE, CND, Vdd, common voltagesignals and the like, in which the common voltage signal is a signal fortransmitting common voltage to the color filter substrate.

[0010] Referring to. FIG. 3, in the case of the liquid crystal displayhaving no PCB 2 and FPC 3, the LOG 9 is additionally formed on the arraysubstrate of the liquid crystal panel as in the liquid crystal displayhaving no FPC. In this case, the LOG 9 is also formed between the gateTCPs 5. Moreover, in order to transmit a common signal to the transfers11 formed at the upper and lower portions of the lift side of the liquidcrystal panel, the common line 10 is formed.

[0011] However, in the prior liquid crystal display having no gate PCBand FPC, since the LOG that is additionally formed on the arraysubstrate must be formed to have low resistance, but this requirement isrestricted by a spatial problem so that the problem of screen quality iscaused.

[0012] Namely, although the adjustment of resistance of the LOG is verycritical to avoid the problem of screen quality of the liquid crystaldisplay having no FPC, it is difficult to adjust the resistance of theLOG to a suitable level, due to the spatial restriction. For thisreason, the problem of output of the gate driver IC can be caused, andthus, the problem of screen quality of the liquid crystal display canoccur.

[0013] Particularly, in the case of the common line in the LOG line, ifthe transfers are formed on a gate pad region, there will be defined aregion in which the common line will be formed. For this reason, otherlines need to be formed on the remaining regions other than this commonline region, and thus, the spatial restriction will be serious. In thiscase, the transfers are usually formed to have a size of 0.5-1.5 mm. Inaddition, since specifications of pin arrangements in the driver IC arelimited, this problem will be more serious.

SUMMARY OF THE INVENTION

[0014] Accordingly, the present invention has been made to solve theabove-mentioned problems occurring in the prior art, and an object ofthe present invention is to provide a liquid crystal display having nogate PCB and FPC, which can prevent the deterioration of screen qualitycaused by LOG line resistance.

[0015] To achieve the above object, the present invention provides aliquid crystal display having no gate PCB and FPC, which comprises: aliquid crystal panel formed by an assemble an array substrate and acolor filter substrate with a liquid crystal layer interposedtherebetween; a plurality of source TCPs and gate TCPs, which areattached to a source and a gate of the liquid panel, respectively, andmounted with a gate driver IC and a source driver IC, respectively; asource PCB connected to the source TCPs and serving to apply a givendriving signal to the source driver IC; a LOG formed on the liquidcrystal panel such that a signal from the source PCB is applied to thegate driver IC via the gate TCPs; and transfers formed between thesubstrates at edges of the liquid crystal panel such that common voltageis applied to the color filter substrate; in which the LOG consists ofgate driver IC-driving signal lines without having a common line forconnecting the transfers with each other.

[0016] According to the present invention, there is no common line inthe LOC so that a margin in a LOG layout can be ensured. This can reducethe resistance of the LOG to a suitable level and thus improve thescreen quality of the liquid crystal display.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of thepresent invention will be more apparent from the following detaileddescription taken in conjunction with the accompanying drawings, inwhich:

[0018]FIG. 1 is a top view showing a prior liquid crystal display;

[0019]FIG. 2 is a top view showing a prior liquid crystal display havingno FPC;

[0020]FIG. 3 is a top view showing a prior liquid crystal display havingno gate PCB and FPC;

[0021]FIG. 4 is a top view illustrating a common line in a prior liquidcrystal display;

[0022]FIG. 5 is a top view showing an inventive liquid crystal displayhaving no gate PCB and FPC;

[0023]FIGS. 6 and 7 are top views flicker and crosstalk properties of aliquid crystal display according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, a preferred embodiment of the present invention willnow be described in detail with reference to the accompanying drawings.

[0025]FIG. 4 is a top view showing a common line of a liquid crystaldisplay according to the prior art. As shown in FIG. 4, in the priorliquid crystal display, a gate PCB 2 and a common line 10 within aliquid crystal panel are used to transmit a common signal (Vcom) to afirst transfer A formed at the lower portion of the left side of theliquid crystal panel. In this case, the common signal (Vcom) istransmitted to the first transfer A in order to apply common voltage toa color filter substrate 8.

[0026] In a structure having no gate PCB, the common signal can beapplied to the first transfer only when a common line is additionallyformed in the panel. However, since a second transfer B formed at theupper portion of the left side of the panel takes a large area of theLOG, the resistance of the rest of the LOG is increased as compared to acase where the common line is not present without the second transfer.Particularly, if the transfer is formed between gate pads, the LOC willhave more increased resistance.

[0027] According to the present invention, in order to prevent theresistance of the LOC from being increased, the transfer at the upperportion of the left side of the panel is not formed, as shown in FIG. 5.In addition, the common line 10 for connecting the transfers at theupper and lower portions of the panel with each other is not formed inthe LOG 9.

[0028] Namely, the liquid crystal display according to the presentinvention comprises: a liquid crystal panel formed by an assemble of anarray substrate 6 and a color filter substrate 7 with a liquid crystallayer interposed therebetween; a plurality of source TCPs 4 and gateTCPs 5, which are attached to a source and a gate of the liquid crystalpanel, respectively, and mounted with a gate driver IC and a sourcedriver IC, respectively; a source PCB 1 connected to the source TCPs 4and serving to apply a given driving signal to the source driver IC; anda LOG 9 formed on the liquid crystal panel such that a signal from thesource PCB 1 is applied to the gate driver IC via driving signal linesof the gate TCPs 5. In this liquid crystal display, transfers 11 areformed between the substrates at edges of the liquid crystal panel suchthat common voltage is applied to the color filter substrate.Particularly, the LOG 9 consists of the gate driver IC-driving signallines without having a common line for connecting the transfers witheach other. In addition, the gate TCPs 4 comprise the driving signallines without having the common line.

[0029] According to this liquid crystal display of the presentinvention, the area of the common line taking the transfers and the LOG9 can be provided for forming other signal lines, so that the resistanceof the gate driver IC-driving signal lines is reduced. This shortens thedelay of the respective signal lines and thus allows excellent screenquality to be achieved.

[0030] In addition, in the gate TCPs, the common line does not need tobe formed, so that the formation of lines can be simplified.

[0031]FIGS. 6 and 7 are drawings showing flicker and crosstalkproperties of the liquid crystal display according to the presentinvention.

[0032] From FIG. 6, it can be found that the inventive liquid crystaldisplay where the LOG has no common line and thus a common signal is notinputted shows better flickers at each gray scale, as compared to theprior liquid crystal display where a common signal is normally inputtedthrough the common line of the LOG.

[0033] From FIG. 7, it can be found that the inventive liquid crystaldisplay and the prior liquid crystal display show substantially similarresults on all horizontal and vertical crosstalk properties. Thisindicates that the elimination of the common line has no effect on thecrosstalk properties.

[0034] As described above, according to the present invention, thecommon line is eliminated from the LOC of the liquid crystal displayhaving no gate PCB and FPC, so that the resistance of the LOC can becomethe desired level. Thus, the output of the gate driver IC can bestabilized, and particularly, the delay of the respective signal linescan be reduced, thereby improving the screen quality of the liquidcrystal display.

[0035] Although a preferred embodiment of the present invention has beendescribed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

What is claimed is:
 1. A liquid crystal display having no gate PCB andFPC, which comprises: a liquid crystal panel formed by an assemble anarray substrate and a color filter substrate with a liquid crystal layerinterposed therebetween; a plurality of source TCPs and gate TCPs, whichare attached to a source and a gate of the liquid panel, respectively,and mounted with a gate driver IC and a source driver IC, respectively;a source PCB connected to the source TCPs and serving to apply a givendriving signal to the source driver IC; a LOG formed on the liquidcrystal panel such that a signal from the source PCB is applied to thegate driver IC via the gate TCPs; and transfers formed between thesubstrates at edges of the liquid crystal panel such that common voltageis applied to the color filter substrate; in which the LOG consists ofgate driver IC-driving signal lines without having a common line forconnecting the transfers with each other.
 2. The liquid crystal displayof claim 1, wherein the gate TCPs comprise the driving signal lineswithout having the common line.